This has been a banner year for me as far as vireos are concerned. Though I’m always on the alert for new birds, I unintentionally backed into a new personal milestone. I was so fixated on warblers during May’s migratory festivities that I didn’t realize until June that I’d spotted every species of vireo expected in northeastern North America. Actually, with the inclusion of our Thick-billed Vireo sighting in the Bahamas in January, I’ve actually seen every vireo of the eastern U.S. this year except one, the highly localized Black-whiskered Vireo of south Florida and the West Indies. Further incentive for a trip to the Florida Keys, as if I needed any.
Vireos are New World passerines in the family Vireonidae. Though that family is divided into four genera, all U.S. vireos are of the genus Vireo. Most vireo species are native to Mexico, Central and South America and tend to be non-migratory. Our local breeders all buck those trends but do share a primarily insectivorous diet with their homebody kin. Superficially similar to wood warblers, vireos are distinctive for their more mellow behavior and less flashy plumage. Drabness seems to define these birds; their name itself descends from the Latin for “green” or “greenish” but the folks that came up with that appellation certainly weren’t thinking chartreuse or lime. However, it’s not the subdued coloration of vireos that makes them tough to spot, but rather their tendency to keep to the tops of trees. Were it not for their complex and distinctive songs, many vireos might go entirely unnoticed.
Considering how challenging these cryptic, canopy-hugging birds are to come by, you’d be right to wonder how a birder of my limited expertise managed to record the whole roster last month. Hey, I’m not proud. I’m happy to admit that, while I sought out some, I stumbled upon others and wouldn’t even have been able to ID certain species without help, whether online or on-location. Still, a bird on your list is worth two in the bush and to celebrate the addition of some of the following to mine (list, not bush), I’ve uncovered a fun fact about each vireo of the American Northeast.
- The Blue-headed Vireo (V. solitarius) was once known as the Solitary Vireo. That species was split by the AOU into three distinct species in 1997. In the divorce, the Blue-headed Vireo got to keep the eastern U.S. and Canada while Plumbeous (V. plumbeus) was granted custody of the Rockies and Great Basin and Cassin’s (V. cassinii) got the West Coast.
- The Philadelphia Vireo (V. philadelphicus) may have been discovered near the City of Brotherly Love, but nearly 90% of these birds breed in the boreal forest of Canada.
- The Red-eyed Vireo (V. olivaceus) is a common sight in eastern forests. The male of the species is sometimes called the “preacher bird” on account of its incessant, monotonous, unmusical vocalizations.
- The Warbling Vireo (V. gilvus) is distinctive for lacking visual distinction; its primary descriptor is an utter absence of field marks. However, as you might surmise from its name, it sure can sing.
- The White-eyed Vireo (V. griseus) earns its name from its remarkable white irises. That white iris is unique among vireos. The bird’s preference of thickets over trees is fairly singular as well.
- The Yellow-throated Vireo (V. flavifrons) is most likely to be confused not with another vireo, but with the Pine Warbler, which, though less brilliant, enjoys the same coloration and habitat.
White-eyed Vireo…lousy photo, beautiful bird